Thermal transport in graphene/h-BN lateral heterostructures with interface compositional diffusion

The synthesis of two-dimensional lateral structures is often associated with compositional transition, causing graded interfaces. Our molecular-dynamics simulations show that the graded interface can significantly increase the thermal resistance of graphene/h-BN lateral heterostructures. The thermal conductivity is therefore lowered depending on the length of the interface diffusion. The phonon participation ratio calculations indicate the occurrence of phonon localization in the composition-graded heterostructures. Meanwhile, thermal rectification is observed in the graphene/h-BN lateral heterostructures, and the heat transport from h-BN to graphene is favored, particularly in the system with abrupt interface. These results provide critical information for the novel design of two-dimensional lateral heterostructures in terms of thermoelectrics and thermal diodes